Tuesday, May 1, 2018

Stribog+ assembly


I managed to assemble the Stribog+ in a bit more than a week.

I started with the fuselage rear part. I cutted the lips receiving the rear cap to keep them 5mm large. Then I installed the brass threated adaptor (MpJet) and the metal clevises. The adaptor is pinched and glued, after removing the teflon on 10mm on the snake rod.

Finally, I could put the tails in place and glue the elevator control horns at the optimum position to obtain the needed throws, and not having the clevises touching each other.

The tails centering pins are glued with a drop of cyano, otherwise, they are staying on the fuselage when removing the tails.

The reap cap need also some cutting allow the control horns to move. I did it progressively, using a mini drill.

Let's continue with the wiring and connectors. They were provided with my Stribog+, but having my habits, I made my own wire harness. In the fuselage, I glued 2 x 1mm wood plate with a 2mm recess on each side in order to create a stop point for the plug. Then the plugs are glued in place with rapid epoxy.

The routing of the wire to the nose is very easy in absence of a ballast tube in the fuselage.

The Servo tray is in place and prepared for the standard 12mm servo size. Absolutely no rework here, the servo enters without forcing on wires. I used the HV6125e screwed with 4 MPjet screws (very good quality). Once elevator servos in place, I finished the eletor snakes with brass threated adaptor and plastic clevises from MPjet (again ;)! ). To secure the elevator sleeves, I used some epoxy paste from UHU. You just mix the paste together, and apply, and let cure.



As receiver battery I used the usual LiIon 18650 2.9Ah with a servo connector as balancer plug, if needed. More info can be found here:

https://planet-soaring.blogspot.fr/2016/02/li-ion-2-cells-battery-soldering.html

Wing servos installation. This time, LDS was provided apart, so I had to installed them. The installation is pretty straight forward. I started by connecting the epoxy arms in the control surfaces, using the tool provided (a long brass rod with a threated pipe at the end). the mounting was so tight that I needed to grid a bit to free the movement. Once completed, I just glued the servo frames in place with the servo head and servo in place to adjust the position with the control surface at the neutral position.

As you can see on the pictures, I mounted 4 HV6130 from MKS. I usually use the 6625 and 6625 mini, but I have been contacted by MKS USA to test the new gear train. In fact I received 2 upgraded 6130 and 2 new 6130 already with the new gear train. I have mounted them radomly as I couldn't distinguish them from  eachother.

The mounting of the LDS with the 6130 is very very tight, and there is no slop at all. I will monitor closely how the servo behaves with time, and under heavy sollicitation.

The servo 6 pins connectors are glued in place with rapid epoxy on the root of the wings. The assembly finishes with the cutting, ajustement and taping of the servo covers in place.

I needed about 200grs of balance lead. It is located in the nose (100grs) and on top of the battery. The empty flying weight is 2380grs with a CoG at 106mm, exactly the same as the Stribog.

For the throws, I just reused the model memory on my radio, and just tune the neutral position, but for the rest, it is identical.

Before to run to the slope, I created the spreasheet for the ballast that give the best ballast slugs combination and the variation of CoG when increasing the ballast with correction when needed (Many thanks to Alvaro Silgado for sharing this very useful excel macro).


Stribog+ assembly

I managed to assemble the Stribog+ in a bit more than a week. I started with the fuselage rear part. I cutted the lips receiving the ...